Has anyone tested "Deep Black" MgAl, <10µm?

[Potassiumchlorate]

If so, how was it compared to Mg of say <63µm?

[optimus]

I don't have the exact spec at hand, but I have tested some 'dark' MgAl. Most powerful flash I ever made, would self-confine at about 0.3g. Only planned to use it for crossettes but never got round to it.

[Potassiumchlorate]

Oh, I forgot: I don't intend to use it for flash. It's for stars, so the light output is the important thing. I have endless problems with the humid air where I live, destroying my parlonstars with Mg.

[Potassiumchlorate]

No-one else having tested it? I know at least one source in Europe, but I don't want to waste tens of € on it, if it isn't at least superior to 63µm Mg.

[psyco_1322]

Dude, you don't need any Magnesium that fine, it's a fire hazard in a bag. Finer is not going to solve your humidity problems.

 

Now, your thread title says MgAl, and everywhere in the thread you say Mg, which is it? You don't really need anything finer that 325mesh for colored stars, 200 will work fine. You really should be using MgAl in your stars, it's not as reactive to water and your stars should keep fine. If you aren't binding with the parlon, using a solvent, then water is going to happily soak into your stars. If you can't get MgAl, then maybe you should look into making it.

[Potassiumchlorate]

*Sighs*

 

I'm using magnesium now. I'm considering changing to magnalium due to the humidity.

 

What I want to know is how good the performance of <10µm magnalium is compared to magnesium. Magnalium has an inferior performance, but <10µm is very fine, so it might compensate quite a bit.

[psyco_1322]

10 microns is like 1200 mesh, I doubt that the powder is even that fine. Can you not get some 325mesh magnalium? It works just fine in colored stars.

[pyrojig]

400-mesh and finer Magnal makes for a "super flash" . It is by far the fastest flash I have ever played with. Self confining in .5 g or less. Side by side with 5413 there is no comparison , Magnal is incredibly faster. Im considering it for crossetts as well.

[Potassiumchlorate]

10 microns is like 1200 mesh, I doubt that the powder is even that fine. Can you not get some 325mesh magnalium? It works just fine in colored stars.

 

I already have 325 mesh MgAl, but I want the finest possible.

 

I'm not sure whether the 10µm claim is true or not, but the colour is very different from the "coarser" MgAl.

[psyco_1322]

I already have 325 mesh MgAl, but I want the finest possible.

 

I'm not sure whether the 10µm claim is true or not, but the colour is very different from the "coarser" MgAl.

 

Most charts list 10 micron as being 1250 mesh. This is not a situation were finer is better. Metal that fine is going to really increase the sensitivity of the comp. 325 will all burn up in the star flame, it's not going to leave any tails. Look at some of the videos from the PGI thread, those colors were made with 325 mesh magnalium.

[Potassiumchlorate]

OK, I'll go for the 325 mesh then, unless the weather becomes dry again this winter, in which case I will continue using Mg

[psyco_1322]

What formulas are you using it in?

[Potassiumchlorate]

Bleser Red Mg:

 

Strontium nitrate 55

Magnesium 28

Parlon 10

PVC 7

 

Bleser White Mg:

 

Barium nitrate 53

Potassium nitrate 12

Magnesium 28

Parlon 7

 

Shimizu Red Star Brilliant:

 

Potassium perchlorate 30

Strontium nitrate 20

Magnesium 30

Parlon 18

Lampblack 2

[psyco_1322]

I like the Klumac Red/Green. They may come out better with the magnalium since they are formulated around it.

 

Strontium Nitrate 50

Potassium Perchlorate 15

Parlon 12

Magnalium, granular, -325 mesh 10

Red Gum 8

Dextrin 5

[Potassiumchlorate]

But does anyone have any idea what Mg sizes "correspond" to what MgAl sizes? Is the light output about equally good for, say, the cheaper and easier-to-get 45µm MgAl as for the 63µm Mg?

 

I have only used 63µm MgAl in Electric Magenta, and it was OK but of course not as good as pure Mg of the same size.

Edited September 13, 2012 by Potassiumchlorate

[taiwanluthiers]

10um MgAl seems fairly reactive... I've never heard of something like this. 45um MgAl is good enough for most stars...

[Potassiumchlorate]

I know one very experienced guy in my own country who mills his MgAl, until it becomes something similar to this. I don't like the idea of milling metals myself, though, since a pyrophoric reaction might be caused etc.

 

I don't know about the reactivity. Magnesium becomes very reactive at about 40µm. Aluminium must be milled down to <5µm, though. Magnalium should be somewhere in the middle.

Edited September 13, 2012 by Potassiumchlorate

[AirCowPeacock]

Not necessarily, but your probably right. However it would be hard to know when to stop your mill unless you dId very frequently checks on the bottom 10% partical size.

[Mumbles]

I know who you're talking about actually.

 

I've gotten the impression from passfire that he mills his MgAl so that his stars (and prime) stay lit at high speeds. This would indicate to me a relatively vigorous burn. Clearly it doesn't matter how wonderful the color might be if they don't stay lit. He also seems to understand that MgAl is superior to Mg from an adverse reaction point of view. Neither Mg or very fine MgAl should be bound with water though. He does seem to be a fan of binding with non-aqueous solvents and binders such has phenolic resins and particularly PVB.

 

He has noted that he mills the MgAl with steel balls for 6hr in a sponnenburgh type mill. He then cracks the cap, and leaves it for a week to slowly oxidize as it sees fit. From there he screens it out and collects the metal powder. There is no indication to how fine it actually is, though he does describe it as a dark grey impalpable powder.

 

Given that the majority of the pyro community has gotten away from using magnesium if at all possible, I don't know of any correlations. They're both going to work just fine. If some property isn't up to your standards from the start, there is always the ability to tweak it.

 

You could always do the reasonable thing, and start coating your magnesium. This would more than likely end your problems. It's been common knowledge for over 30 years that even with a parlon coating, treated magnesium is still a good idea.

 

I'm still not sure why you're so obsessed with color purity. Magnesium and magnalium at the distance of shell breaks will look almost identical. Much like with unattractive women, distance can do wonders to hide imperfection.

[psyco_1322]

You are trying to compare apples to oranges, just because they both come from a tree and you can make your morning juice from either one, doesn't mean you will get your citrus desires from your apples. But they will still both cure your thirsty morning mouth.

[mabuse00]

The formulas you posted are meant to use rather coarse Mg, 100mesh, Shimizu's brilliant formulas are often quoted with 60mesh.

 

I would expect this to be roughly comparable to 45µm MgAl in terms of reactivity.

 

 

Is the light output about equally good for, say, the cheaper and easier-to-get 45µm MgAl as for the 63µm Mg?

 

The light output per burned mass of fuel will be better with Mg.

Also the purity will be better.

Your 10µm stuff will burn faster than the coarser MgAl grades, that's all. There will be no difference in color, maybe the stars burn brighter, but that's just because they burn faster.

 

Also you cannot substitute Mg for MgAl 1/1, because aluminium needs more oxygen.

 

 

I have endless problems with the humid air where I live, destroying my parlonstars with Mg.

Are you sure it's the humidity, and not undried consumer stuff acetone?

What exactly happens, how do they appear, smell ect?

I was under the impression that parlon coated stuff will at least last some time. I remember even reading somewhere that somebody was even using parlon for coating Mg.

 

I did some tests with NaNO3/Mg flares in the summer, but I had only 63µm Mg then, and - lacking a press - pumped the 20mm stuff with a syringe. It burned far to fast to be useful of course. But even after 2 month of storage in the misty, fungi ridden cellar I could not see much deterioration.

 

I used PVB as the binder, with isopropanol as solvent. Isopropanol can be bought with 99,X% purity, what means it's not dry but contains less water than commercial acetone or denatured acohol. I have to gain more experience with that stuff, but it might be a solution.

 

 

 

Anyway, there must be a way to work with Mg, and it IS clearly superior to MgAl.

How about those military flares, the last for decades and use Mg to.

 

I'm about to try Mg stars myself soon, just ordered some 200µm Mg

Edited September 13, 2012 by mabuse00

[Potassiumchlorate]

The formulas you posted are meant to use rather coarse Mg, 100mesh, Shimizu's brilliant formulas are often quoted with 60mesh.

 

I would expect this to be roughly comparable to 45µm MgAl in terms of reactivity.

 

Hm, I've been using 63µm Mg but I have 40µm Mg too, but you mean even 63µm Mg is too fine? So for what do people use so extremely fine Mg, for powerful small salutes?

 

 

The light output per burned mass of fuel will be better with Mg.

Also the purity will be better.

Your 10µm stuff will burn faster than the coarser MgAl grades, that's all. There will be no difference in color, maybe the stars burn brighter, but that's just because they burn faster.

 

Also you cannot substitute Mg for MgAl 1/1, because aluminium needs more oxygen.

 

This is what I mean. MgAl would only be a last resort anyway, since Mg will always be superior.

 

Are you sure it's the humidity, and not undried consumer stuff acetone?

What exactly happens, how do they appear, smell ect?

I was under the impression that parlon coated stuff will at least last some time. I remember even reading somewhere that somebody was even using parlon for coating Mg.

 

I did some tests with NaNO3/Mg flares in the summer, but I had only 63µm Mg then, and - lacking a press - pumped the 20mm stuff with a syringe. It burned far to fast to be useful of course. But even after 2 month of storage in the misty, fungi ridden cellar I could not see much deterioration.

 

I used PVB as the binder, with isopropanol as solvent. Isopropanol can be bought with 99,X% purity, what means it's not dry but contains less water than commercial acetone or denatured acohol. I have to gain more experience with that stuff, but it might be a solution.

 

 

 

Anyway, there must be a way to work with Mg, and it IS clearly superior to MgAl.

How about those military flares, the last for decades and use Mg to.

 

I'm about to try Mg stars myself soon, just ordered some 200µm Mg

 

I have no idea whether it's water in the acetone being the main cause, though it seems that the extremely moist weather has worsened this problem.

 

The stars don't smell of ammonia to start with, but I noticed it after a couple of months. I have some parlon stars from 2009, and they don't smell at all. It also seems like the bigger the stars are, the more do they attract/trap moist. Stars smaller than 10mm usually don't smell at all.

 

I have been thinking of red gum as the binder and isopropanol as the solvent. It seems like they burn better and with almost no tendency to get a "tail" when bound with red gum. I don't know how well the red gum protects the Mg, though.

 

When it gets colder outside and the air humidity gets down to a reasonably low level, I'll test with both acetone and xylene as solvents, and see whether xylene seems to work better.

[pyrojig]

I have to say , the really fine Magnal can be reactive, and produce the annoying H-sulfide gas. I had a batch of the Bleser wht strobe get stinky on me this week. I quickly added boric acid sol. to the mix as I felt the temp rise. It did help slow down the already reacting mix. After letting it dry, I was not sure if the boric acid would have a ill effect on the strobe . I was happy to report it was perfectly fine. On those same lines, Red gum will NOT protect like parlon will. Mag is still going to degrade if nitrates are present in the prime or the main mix. I too have had parlon stars last years w/o degrading .

 

 

Hm, I've been using 63µm Mg but I have 40µm Mg too, but you mean even 63µm Mg is too fine? So for what do people use so extremely fine Mg, for powerful small salutes?

 

 

 

 

This is what I mean. MgAl would only be a last resort anyway, since Mg will always be superior.

 

 

 

I have no idea whether it's water in the acetone being the main cause, though it seems that the extremely moist weather has worsened this problem.

 

The stars don't smell of ammonia to start with, but I noticed it after a couple of months. I have some parlon stars from 2009, and they don't smell at all. It also seems like the bigger the stars are, the more do they attract/trap moist. Stars smaller than 10mm usually don't smell at all.

 

I have been thinking of red gum as the binder and isopropanol as the solvent. It seems like they burn better and with almost no tendency to get a "tail" when bound with red gum. I don't know how well the red gum protects the Mg, though.

 

When it gets colder outside and the air humidity gets down to a reasonably low level, I'll test with both acetone and xylene as solvents, and see whether xylene seems to work better.

[Potassiumchlorate]

Well, well, I can always coat it with dichromate, if I decide to continue using pure Mg.

[pyrojig]

Yes indeed!

I guess that boric acid has a adverse reaction with Magnesium . ,while dichromate is superior . Al is the opposite and needs the boric acid to stop the reaction .

I too have made a few comps recently with Mag.100-200mesh , and I must say it is crazy bright , and I love that sizzle you get out of it!